1. Field of the Invention
The present invention relates to an electrical, fan-cooled, in particular, hand-held tool.
2. Description of the Prior Art
In powerful electrical tools, in particular, in electrical hand-held tools instead of universal motors, brushless electrical motors are used and which include an inverted rectifier and a constant voltage d.c. link with a link condensator for an intermediate power storage. The losses associated with the storage lead to heating of the link condensator which has, in comparison with the inverted rectifier and the electrical motor, a lower limiting temperature.
U.S. Pat. No. 6,127,751 discloses a hand-held power tool in which both the electrical motor and the motor electronics are arranged parallel to each other in an air stream of a fan located in the air flow direction downstream of the electric motor and the motor electronics.
German Publication DE-100 21 356 discloses cooled brushless electric motor and inverted rectifier which, according to U.S. Pat. No. 4,766,963, are arranged between inlet and outlet openings of a housing parallel to each other within an air stream produced by a ventilator. The components, which have different limiting temperatures are cooled in parallel by the same air stream. As a result, the cooling potential of the air stream is not used optimally. In this tool, there is no link condensator.
U.S. Pat. No. 5,331,239 discloses a compact motor-inverted rectifier unit with a brushless electric motor, inverted rectifier, constant voltage d.c. link with a link condensator, and a fan the air stream of which firstly cools the link condensator and then is separated in two streams for cooling the electric motor and the inverted rectifier. However, a compact motor-inverted rectifier unit is not suitable for electrical tool, in particular for electrical hand-held tool with separated free chambers in the tool housing.
Accordingly, an object of the present invention is an electrical tool with a fan and a link condensator and in which the air stream is used optimally.